The US Tennis Association announced Monday that Roddick was hurt during his historic loss Sunday to Roger Federer at the All England Club -- a match that finished 16-14 in the longest fifth set in Grand Slam final history.

Roddick slipped and tumbled to the grass in the eighth game of the fourth set. He stayed down for a few moments, then rose, grimacing, and toweled off.

The 26-year-old American went on to play for more than another hour, finally succumbing when Federer broke him for the first time all match in the 77th and last game.

After the match, Roddick was asked whether he hurt himself in that fall, and he replied, "No. It was OK."

He is being replaced on the US Davis Cup team by Mardy Fish, who reached the third round at Wimbledon. Roddick is ranked No 6, while Fish is No 23.

Roddick had played in 18 consecutive Davis Cup matches for the United States, helping the country win the 2007 title. "Andy has been a stalwart for this team the past nine years, and his dedication to Davis Cup and his teammates is unquestioned," US captain Patrick McEnroe said.

Croatia hosts the US on clay at Porec, Croatia, starting Friday.

"Mardy is a Davis Cup veteran and we appreciate his willingness to join the team on short notice. He has been playing well and we are glad to have him back in the singles lineup," McEnroe said. "Andy had a great run at Wimbledon. He battled for more than four hours yesterday and fought hard to reach the final. Understandably, his body is not up for the rigors of Davis Cup in such a short turnaround."